New answer which is identical to mine

As I was scrolling through the new questions of MSE, I thought of checking out some of my previous unaccepted answers and learn something from the accepted answers.

And it happened that a question($g(x) = e^{f(2x)}, f(2) = 0, f'(2) = 1$, then what is $g'(1)?$) which I had answered two days ago has received a new answer just three hours ago which is identical to mine.

There are many instances when I would be typing out the answer and would have to discard as some other user would have already provided the same thought as mine. Also, some hours difference (as we all have different time zones) would also make no difference as such.

I don't have any problem with the other answer, I just want to know that whether more than one answers speaking of exactly the same thing allowed?

• If you suspect they just copied, I would flag for moderator attention. If they independently came to the same answer, I would think it’s not against any rules. in either case it might be downvoted or deleted (your specific example is now downvoted ) Jul 19 at 2:40
• @CalvinKhor Sir if it isn't against any rules ,I don't have any issue with the answer as it is most probably not copied (because from the about section it seems the user is a PhD student whereas I am just a highschool student).
– user1078285
Jul 19 at 2:50
• Well, I didn't vote this time. But the answers are quite similar. In general though, even if the proof or idea is the "same", sometimes the presentation can be very different and then it is worth keeping both versions around. Another case is one user providing a sketch, and a different user writing a full proof Jul 19 at 3:06
• @Calvin But that user has also duplicated other answers too, e.g. this essentially duplicates an answer posted $3$ years prior. Jul 19 at 9:41
• @BillDubuque well. That’s the sort of stuff I hope mod flags help catch. Jul 19 at 11:47